CN105735371A - Frequency-conversion horizontal cyclic loading test device - Google Patents

Abstract

The invention relates to a frequency-conversion horizontal cyclic loading test device and aims at providing the frequency-conversion horizontal cyclic loading test device which is simple in structure, low in cost, large in loading frequency and various in loading manner. According to the technical scheme, the frequency-conversion horizontal cyclic loading test device is provided with a model pile arranged in a water trough. The frequency-conversion horizontal cyclic loading test device is characterized in that a plurality of loading mechanism sets are connected to the model pile; each loading mechanism set is composed of a gravity loading mechanism and a moment loading mechanism, wherein the gravity loading mechanism and the moment loading mechanism are symmetrically connected to the two sides of the model pile; and each gravity loading mechanism is provided with a weight block I and a steel wire rope I, wherein one end of the steel wire rope I is connected to the model pile, the other end of the steel wire rope I is connected with the weight block I, the steel wire rope I is hung on a pulley I, and the pulley I is fixed to the ground through a connecting rod I and a rigid loading frame. The frequency-conversion horizontal cyclic loading test device is suitable for conducting long-period horizontal cyclic researches on an offshore single pile indoor model test.

Description

Frequency conversion horizontal cyclic load testing machine

Technical field

The present invention relates to a kind of frequency conversion horizontal cyclic load testing machine.It is applicable to marine single pile indoor model test and carries out long period horizontal cyclic research.

Background technology

At present, pile foundation or the application in ocean engineering of other base form are more and more extensive, but due to maritime environment complex, are frequently subjected to the stormy waves load action of different frequency, and the action period is long, and number of loading often reaches 10⁷Secondary, cause impact to the horizontal load-bearing performance study of indoor single pile.When therefore marine single pile indoor model test being carried out long period horizontal cyclic research in the past, generally the external load of different frequency is simplified to a load and is applied in Model Pile, load frequently with the vibrator of somewhat expensive or MTS hydraulic loading system during loading, and have following drawback:

1, loading equipemtn somewhat expensive, single device expense reaches tens thousand of unit to millions of units not etc., and testing expenses are high.2, the number of times loaded is limited, and when loading number of times and reaching hundreds thousand of times, loading system easily goes wrong.3, the requirement of satisfying personalized test it is difficult to.The load that most of vibrators or MTS hydraulic loading system apply is relatively big, generally with kN for linear module.And often required in model test load only needs tens N to the load of hundreds of N, loading accuracy is difficult to meet the requirement of mini Mod test.4, being limited to volume and the test site of vibrator or MTS hydraulic loading system, often only carry out single-point loading during test, the research contents making test is limited.

Summary of the invention

The technical problem to be solved in the present invention is: for above-mentioned Problems existing, it is provided that the frequency conversion horizontal cyclic load testing machine that a kind of simple in construction, loading number of times less costly, high and loading form are various.

The technical solution adopted in the present invention is: a kind of frequency conversion horizontal cyclic load testing machine, there is the Model Pile being placed in tank, it is characterized in that: be connected to some load maintainer groups in described Model Pile, load maintainer group is connected to a gravitational load mechanism of described Model Pile both sides by symmetry and a moment load maintainer forms；

Described gravitational load mechanism has counterweight block I and steel wire rope I, and steel wire rope I 1 end is connected to described Model Pile, and the other end connects counterweight block I, and this steel wire rope I is hung on pulley I, and pulley I is fixed on ground through connecting rod I and rigidity loading frame；

Described moment load maintainer has steel wire rope II and gravity center shift mechanism, ground is fixed on through rigidity loading frame in gravity center shift mechanism, and be rotatably connected by horizontally disposed rotating shaft between gravity center shift mechanism with rigidity loading frame, gravity center shift mechanism connects described Model Pile through steel wire rope II, this steel wire rope II is hung on the pulley II above gravity center shift mechanism, and this pulley II is fixed on ground through connecting rod II and rigidity loading frame.

Described gravity center shift mechanism has line slideway, scale pan and the counterweight block II being placed on scale pan, wherein line slideway one end is rotatably connected rigidity loading frame through described rotating shaft, line slideway is connected with described steel wire rope II, described scale pan is movably disposed within described line slideway, this scale pan is connected to can drive scale pan away from the actuating mechanism moved near rotating shaft.

Described actuating mechanism includes the steel wire rope III and the balancing weight that are connected to scale pan one end, and it is connected to the steel wire rope IV of the scale pan other end, chain extension bar and motor, wherein chain extension bar one end connecting steel wire ropes IV, the other end is connected in the rotating shaft of motor, and chain extension bar is along machine shaft radial arrangement.

The invention has the beneficial effects as follows: 1, experimental subject can be carried out the horizontal addload of long period high reps by the load testing machine of the present invention.2, the loading that can realize load amplitude less requires (10¹N～10²N), load amplitude can be adjusted by the weight of counterweight block.3, can loading along the differing heights of Model Pile pile body or other structure, load(ing) point can require personal settings according to specific experiment.4, load testing machine of the present invention loading cycle and load number of times in theory can be unlimited, depend primarily on motor performance.5, can consider to load the load (motor adopting different frequency can realize) of different frequency, wind as different in Loading frequency, the function demand of wave load simultaneously.6, motor separates with loading object, it is to avoid because the frequency of vibration of motor, with interactive construction, potential covibration occurs, reduce the factor affecting model test to greatest extent.

Accompanying drawing explanation

Fig. 1 is the structural representation of embodiment 1.

Fig. 2 is the structural representation of embodiment 2.

Detailed description of the invention

Embodiment 1: as it is shown in figure 1, the present embodiment is a kind of single-point frequency conversion horizontal cyclic load testing machine, having the Model Pile 1 being placed in tank, the added rigidity loading frame 2 having door type of Model Pile 1, rigidity loading frame 2 is fixedly installed on ground.Being connected to one group of load maintainer group in this example Model Pile 1, this load maintainer group is connected to a gravitational load mechanism of Model Pile 1 both sides by symmetry and a moment load maintainer forms.

In the present embodiment, gravitational load mechanism has counterweight block I 9 and steel wire rope I 3, one end of steel wire rope I 3 is connected to Model Pile 1, the other end connects counterweight block I 9, this steel wire rope I 3 is hung on pulley I 7, pulley I 7 is installed on rigidity loading frame 2 through connecting rod I 5, and the installation site of pulley I 7 is that level is as the criterion to ensure steel wire rope I 3 and Model Pile 1 linkage section.

In this example, moment load maintainer has steel wire rope II 4 and gravity center shift mechanism, gravity center shift mechanism has line slideway 12, scale pan 11 and the counterweight block II 10 being placed on scale pan 11, wherein line slideway 12 one end is rotatably connected on rigidity loading frame 2 through horizontally disposed rotating shaft 13, scale pan 11 is movably disposed within line slideway 12, this scale pan is connected to can drive scale pan 11 away from the actuating mechanism moved near rotating shaft 13.In the present embodiment, actuating mechanism includes being connected to scale pan 11 and connects steel wire rope III 15 and balancing weight 16 near rotating shaft 13 end successively, and steel wire rope III 15 is hung on pulley, and pulley is installed on rigidity loading frame 2；Scale pan 11 connect steel wire rope IV 14, chain extension bar 17 and motor 18 (frequency modulation motor) successively away from rotating shaft 13 end, motor is fixed on ground through installing rack 19, chain extension bar 17 one end connecting steel wire ropes IV, the other end is connected in the rotating shaft of motor 18, and chain extension bar 17 is along motor 18 rotating shaft radial arrangement.The middle part of the present embodiment cathetus guide rail 12 is through steel wire rope II 4 link model stake 1, this steel wire rope II hangs on the pulley II 8 being positioned at above line slideway 12, this pulley II is installed on rigidity loading frame 2 through connecting rod II 6, and the installation site of pulley II 8 is that level is as the criterion to ensure steel wire rope II 4 and Model Pile 1 linkage section.

The operation principle of the present embodiment is as follows: after load testing machine installs, according to the amplitude N that is further applied load needed for concrete test, by calculating mass M and the m obtaining required counterweight block I 9, II 10, after counterweight block I, II is positioned over relevant position, start motor 18.By the mechanical reciprocation of counterweight block II 10 and scale pan 11, constantly change the acting force arm of counterweight block II 10, principle of moment balance just can export the Simple Harmonic Load of required horizontal loading amplitude.

In this example, load testing machine mainly utilizes the principle of moment balance in mechanics to realize being converted into the gravity of counterweight block horizontal force, and the pulling force T of II 4 pairs of line slideways 12 of steel wire rope and gravity G countershaft 13 AnchorPoint of gravity center shift mechanism make equalising torque:

$\left\{\begin{array}{c}\mathrm{\Σ}{M}_O=0=G\·x+T\·a\\ T=F\end{array}\right.$

Owing to the position of pulley II 8 is fixed, therefore arm of force a is fixed value；Owing to scale pan 11 can move back and forth, the center of gravity of gravity center shift mechanism can change back and forth, and arm of force x size is change, for the function relevant to motor 18 rotating disk and rotational frequency, (when motor uniform rotation, x is time dependent SIN function) is changed with electric machine rotation mode.

Finally act on Model Pile 1 on make a concerted effort be:

$N=F-f=G\·\frac{x}{a}-Mg$

In loading procedure, owing to counterweight block II 10 can realize bilateral reciprocation under motor 18 and balancing weight 16 act on so that arm of force x realizes changing over, so that N value of making a concerted effort changes over.The size of mass M and m and arm of force a and x by changing counterweight block I 9, II 10, it is possible to obtain the load N value needed for experimental design.

Embodiment 2: as shown in Figure 2, the present embodiment is a kind of Multi-point frequency-changing horizontal cyclic load testing machine, the structural principle of this load testing machine is substantially the same manner as Example 1, it is different in that the present embodiment adopts five groups of load maintainer groups, the multipoint excitation to Model Pile 1 can be realized according to test demand, load maintainer group is connected to a gravitational load mechanism of Model Pile 1 both sides by symmetry and a moment load maintainer forms, wherein four moment load maintainers and a gravitational load mechanism are positioned on the left of load testing machine, one moment load maintainer and four gravitational load mechanisms are positioned on the right side of load testing machine, in this example, in the moment load maintainer of homonymy, steel wire rope IV 14 is connected on a chain extension bar 17 and motor 18 jointly, in the gravitational load mechanism of homonymy, steel wire rope III 15 is connected on a balancing weight 16 jointly.

Claims (3)

1. a frequency conversion horizontal cyclic load testing machine, there is vertical fixing Model Pile (1), it is characterized in that: be connected to some load maintainer groups in described Model Pile (1), load maintainer group is connected to a gravitational load mechanism of described Model Pile (1) both sides by symmetry and a moment load maintainer forms；

Described gravitational load mechanism has counterweight block I (9) and steel wire rope I (3), steel wire rope I (3) one end is connected to described Model Pile (1), the other end connects counterweight block I (9), this steel wire rope I is hung on pulley I (7), and pulley I (7) is fixed on ground through connecting rod I (5) and rigidity loading frame (2)；

Described moment load maintainer has steel wire rope II (4) and gravity center shift mechanism, ground is fixed on through rigidity loading frame (2) in gravity center shift mechanism, and be rotatably connected by horizontally disposed rotating shaft (13) between gravity center shift mechanism with rigidity loading frame (2), gravity center shift mechanism connects described Model Pile (1) through steel wire rope II (4), this steel wire rope II is hung on the pulley II (8) above gravity center shift mechanism, and this pulley II is fixed on ground through connecting rod II (6) and rigidity loading frame (2).

2. frequency conversion horizontal cyclic load testing machine according to claim 1, it is characterized in that: described gravity center shift mechanism has line slideway (12), scale pan (11) and the counterweight block II (10) being placed on scale pan (11), wherein line slideway (12) one end is rotatably connected rigidity loading frame (2) through described rotating shaft (13), line slideway (12) is connected with described steel wire rope II (4), described scale pan (11) is movably disposed within described line slideway (12), this scale pan is connected to scale pan can be driven away from the actuating mechanism with close rotating shaft (13) movement.

3. frequency conversion horizontal cyclic load testing machine according to claim 2, it is characterized in that: described actuating mechanism includes being connected to steel wire rope III (15) and the balancing weight (16) of scale pan (11) one end, and it is connected to the steel wire rope IV (14) of scale pan (11) other end, chain extension bar (17) and motor (18), wherein chain extension bar (17) one end connecting steel wire ropes IV, the other end is connected in the rotating shaft of motor (18), and chain extension bar (17) is along motor (18) rotating shaft radial arrangement.